How many feet is it normally thought of as ok for crossing a no vis sump on a breath hold? 5', 10', 15'?

I am a diver and free diver. In nice warm clear water I’ve held my breath for 2 minutes at 30' before, but breath hold sump diving is totally different. Even traversing 5 feet with all your gear on seems to take forever. Am I just psyching myself out? There is a trip with a 15' sump coming up. I am trying to decide if I want to do it.

This judgement call is probably different for everyone. 15ft with zero vis and no fixed line sounds crazy to me. Like Larry, under 10 ft with a fixed line on an established route sounds reasonable to me. Maybe a bit more if it was a wide open space with good visibility but it all comes down to what feels safe at the time.

jeffkruse wrote:How many feet is it normally thought of as ok for crossing a no vis sump on a breath hold? 5', 10', 15'?I am a diver and free diver. In nice warm clear water I’ve held my breath for 2 minutes at 30' before, but breath hold sump diving is totally different. Even traversing 5 feet with all your gear on seems to take forever. Am I just psyching myself out? There is a trip with a 15' sump coming up. I am trying to decide if I want to do it.

I wouldn't do it without an established line to follow and you knew for a fact it was a short swim under 10'.

In college back in the late 80's I did a short sump. It was short enough that one of the guys with me would keep hold of my ankle on the entrance side to the sump, I would go under water, stretch out as far as I could and feel one of my hands come up out of the water into air. The passage was maybe 3' floor to ceiling. So once we figured out there was an air pocket I pushed my way through, not knowing what was on the other side as far as quality of air or how much room was available for my head to come above the water. It was actually a large room and all was well. But, I could have come out into bad air, or there not be enough room for my head to rise high enough to breath in a small passage not wide enough for me to turn around and go back. So, it could have turned out bad and I would not be here writing this post, I would be another forgotten statistic from the 80's.

That was then, this is today and now I have a wife, kids and others that depend on me. No way I would do that as I now have appreciation for life and responsibility.

There are much better choices than holding your breath in an underwater cave passage. I'd suggest you take at least a power snorkel. An AL40 with the proper valve will provide you with a bit more wiggle room when it comes to your return trip. A 40, as you probably know, won't really hold you up as you take it to the sump. No matter how short the sump, you need to install a robust and non-floating guideline.If you have not had a cave diving course, this would probably be the best (first) place to start. Sumps can bite back pretty hard as opposed to more "recreational" spring and cenote cave diving. Be safe!

Edit: And by that I mean, what is so important on the other side that you would risk your life over? Who is going to help you if you get in trouble? Thats right, no one, because no one will know you are in trouble.

I have been sump diving for 36 years, and I wouldn't consider doing a low viz breath hold dive. I don't even like to do them in clear water. A 13 cf tank and regulator isn't that big to haul through a cave. That way you can hold your breath, and if you get hung up, you have several minutes to get un-stuck. There was a fatality in south Georgia a few years ago, because a guy did a breath hold dive in clear water, in a fairly large passage.